Well there are two possibilities: 1) Trump's businesses are lower risk and so the lower realized return is as expected 2) there is significant idiosyncratic ri

Well there are two possibilities: 1) Trump's businesses are lower risk and so the lower realized return is as expected 2) there is significant idiosyncratic risk in a single company which can diversified away with the S&P500 while maintaining the same expected return. I disbelieve (1) because of his multiple high-profile bankruptcies.